<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

defined('THINK_PATH') or exit();
/**
 * Redis缓存驱动
 * 要求安装phpredis扩展：https://github.com/owlient/phpredis
 * @category   Extend
 * @package  Extend
 * @subpackage  Driver.Cache
 * @author    尘缘 <130775@qq.com>
 */
class CacheRedis extends Cache {

	/**
	 * 架构函数
	 * @param array $options 缓存参数
	 * @access public
	 */
	public function __construct($options=array()) {
		if ( !extension_loaded('redis') ) {
			throw_exception(L('_NOT_SUPPERT_').':redis');
		}
		if(empty($options)) {
			$options = array (
                'host'          => C('REDIS_HOST') ? C('REDIS_HOST') : '127.0.0.1',
                'port'          => C('REDIS_PORT') ? C('REDIS_PORT') : 6379,
                'timeout'       => C('DATA_CACHE_TIMEOUT') ? C('DATA_CACHE_TIMEOUT') : false,
                'persistent'    => false,
			);
		}
		$this->options =  $options;
		$this->options['expire'] =  isset($options['expire'])?  $options['expire']  :   C('DATA_CACHE_TIME');
		$this->options['prefix'] =  isset($options['prefix'])?  $options['prefix']  :   C('DATA_CACHE_PREFIX');
		$this->options['length'] =  isset($options['length'])?  $options['length']  :   0;
		$func = $options['persistent'] ? 'pconnect' : 'connect';
		$this->handler  = new Redis;
		$options['timeout'] === false ?
		$this->handler->$func($options['host'], $options['port']) :
		$this->handler->$func($options['host'], $options['port'], $options['timeout']);
	}

	/**
	 * 读取缓存
	 * @access public
	 * @param string $name 缓存变量名
	 * @return mixed
	 */
	public function get($name) {
		N('cache_read',1);
		return $this->handler->get($this->options['prefix'].$name);
	}

	/**
	 * 写入缓存
	 * @access public
	 * @param string $name 缓存变量名
	 * @param mixed $value  存储数据
	 * @param integer $expire  有效时间（秒）
	 * @return boolen
	 */
	public function set($name, $value, $expire = null) {
		N('cache_write',1);
		if(is_null($expire)) {
			$expire  =  $this->options['expire'];
		}
		$name   =   $this->options['prefix'].$name;
		if(is_int($expire)) {
			$result = $this->handler->setex($name, $expire, $value);
		}else{
			$result = $this->handler->set($name, $value);
		}
		if($result && $this->options['length']>0) {
			// 记录缓存队列
			$this->queue($name);
		}
		return $result;
	}

	/**
	 * 删除缓存
	 * @access public
	 * @param string $name 缓存变量名
	 * @return boolen
	 */
	public function rm($name) {
		return $this->handler->delete($this->options['prefix'].$name);
	}

	/**
	 * 清除缓存
	 * @access public
	 * @return boolen
	 */
	public function clear() {
		return $this->handler->flushDB();
	}
}